Large eddy simulations using recursive renormalization-group based eddy viscosity

Sumit Vashishtha, Anando Chatterjee, Abhishek Kumar, Mahendra K Verma

Published 2017-12-08Version 1

We have used renormalized viscosity derived using `self-consistent' recursive renormalization-group method to perform large eddy simulations (LES) of decaying homogeneous and isotropic turbulence inside a periodic cubical box on coarse grids ($32^3$, $64^3$ and $128^3$) at initial Taylor Reynolds number, $\mathrm{R_{\lambda}=315} $. The results from LES were compared against direct numerical simulation (DNS) results ($512^3$ grid) at the same initial $\mathrm{R_{\lambda}}$. There is a good agreement between the computed quantities for LES and DNS - temporal evolution of turbulence kinetic energy $\mathrm{E_{t}}$, kinetic energy spectra $\mathrm{E_{u}(k)}$, kinetic energy flux $\mathrm{\Pi_u(k)}$- and the evolution of large scale structures, visualized using the velocity magnitude and finite-time-Lyapunov-exponent isosurfaces, too remain similar for both classes of the simulations. This establishes the suitability of using recursive renormalization-group based eddy viscosity in performing large eddy simulations.